[unreadable] [unreadable] This competing supplement application is submitted to NIDA in response to PAS-03-023, International Research Collaboration on Drug Addiction. It will establish a collaborative research project between investigators from the Center for Adolescent Substance Abuse Research (CeASAR) at Harvard Medical School/Children's Hospital Boston and the Center for the Evaluation, Prevention, and Research of Substance Abuse (CEPROS) in the Czech Republic. The parent grant is Screening and Brief Advice to Reduce Teen Substance Use (1 R01 DA018848), which was funded by NIDA under RFA-DA-04-006, Screening and Intervention for Youth in Primary Care Settings. The parent study is an efficacy trial of a comprehensive prevention/brief advice intervention within a primary care research network. The study uses a noncontemporaneous control group design to test the effect of computerized screening program that provides immediate feedback to the adolescent and a prompt sheet for primary care providers listing advice bullets that are specific to the adolescent's level of drug involvement. Measurements will occur at the annual well care visit, and 3-months and 12-months later. Outcome will be assessed by examining between-groups differences in rates of substance use initiation among non-users, and differences in substance use cessation among users. This competing supplement application will add nine primary care practices in the Greater Prague area. The proposed project includes translation/back translation of the computerized screening program and other study materials into Czech, a validation study of the CRAFFT screen among Czech youth, and a controlled trial of the translated screening and brief advice intervention using methods that parallel those of the parent study. The benefits for the U.S. side will be to (1) build a research collaboration with investigators from the Czech Republic, (2) determine the validity of the CRAFFT screen in a language other than English, (3) increase power of the parent study, (4) gain an understanding of cultural variations in screening/brief advice, and (5) prepare for future cross-cultural studies of adolescent substance abuse. For the Czech side, the benefits will be (1) build a research collaboration with investigators from the U.S., (2) validate a new brief screening test for adolescent substance abuse that is practical for use in pediatric primary care, (3) test a new method of pediatric office screening and brief advice for drug use, (4) gain an understanding of cultural variations in screening/brief advice, and (5) prepare for future cross-cultural studies of adolescent substance use. [unreadable] [unreadable]